KURDACHENKO, L.; SEMKO, N.; SUBBOTIN, I. A generalization of the malnormal subgroups . Reports of the National Academy of Sciences of Ukraine, Kyiv, Ukraine, n. 3, p. 25–28, 2024. DOI: 10.15407/dopovidi2019.03.025. Disponível em: https://nasu-periodicals.org.ua/index.php/dp/article/view/2155. Acesso em: 12 may. 2025.